mor vehicle info would help, but blower motor can be shot without blowing fuse
Could be your fuse, blower, heater core,loose ac belt, thermastatt or low coolant.
heater fan blower motor is burn up not working need to replace it could also be a heater relay typically located on the fuse panel that needs replacing could also be the switch on the switch panel
Blower motor not working: could be the electric motor, or A fuse, or A short. Blower motor working: could be low engine coolant, or A stoped up heater core, or loss of vacumme to the inside of the car from the engine, or A bad water pump, or A bad thermostat.
could be thermostat or heater fan if you can hear all the speeds on the blower motor working then it could be your thermostat but your heater core might be plugged as well
can be the heater blower motor resistor located in either the ductwork or under hood near blower motor on firewall
Could be several things. If the blower works on A/C or vent it is good. If the Heater core is not leaking (due to corrosion, which is a common problem) it is probably good. Could just be the Temperature cable is off the the blower door not allowing air to pass over the heater core. Just to name a few..........
There are probably over 100 potential reasons why they're not working. What the actual reason is... more information would be needed to determine this. For starters, the symptoms. It could be as simple as the blower not working, or it could be something much more complex.
I would check any fuses/relays related to the heater or blower motor. If the heater fan doesn't work, could be a bad heater blower motor resistor(if has one) which are usually inline in the ductwork or out next to the heater blower motor under the hood. If the fan does work w/no heat then could possibly be a bad thermostat(stuck open) or control head.
If a 2000 Grand Am sometimes has the heater blower working and sometimes it won't, the problem could be with the heater relay switch. The heater relay switch lets the heater blower know when to come on and when to go off. In most vehicles this switch is behind the glove compartment. This part sometimes gets corroded from condensation in this area.
I have changed resistor a d blower motor still not working, maybe i missed a fuse or could the control switch not work?
Blown fuse, defective blower motor resistor pack, defective blower motor, or defective fan speed switch.
try check the blower fan itself. although everything is working you will something to move the air.